Griffiths 12.43. A parallel-plate capacitor, at rest in frame S0 and tilted at a 45° angle to the x0 axis, carries charge densities ± σ0 on the two plates (Fig. 12.41). System S is moving to the right at speed v relative to S0. a) Find E0, the field in S0. b) Find E, the field in S. c) What angle do the plates make with the x axis (in frame S)? d) Is the field perpendicular to the plates in S?